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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script>
        var myname = '旗木卡卡西';
        var address = '火影村';
        var age = 30;
        var email = 'kakaxi@itcast.cn';
        var gz = 2000;
        console.log(myname);
        //连续赋值
        var age = 18,
            address = '火影村',
            gz = 2000;
        //只声明不赋值
        var sex;
        console.log(sex);  //undefined 未定义输出
        //不声明不赋值
        // console.log(tel);  //tel is not defined 报错
        //不声明  直接赋值
        qq = 110;
        console.log(qq);   //可以使用，自动声明，会变成全局变量，不提倡使用
        
        //js是动态语言，数据类型依据右边值随时变化
        var x = 20;
        x='pink'; 
        // 八进制以0开头
        var num1=010;
        console.log(num1);//输出结果为8
        //十六进制0x
        var num2=0xa;
        console.log(num2);//输出结果为10

        //数字型的最大值
        console.log(Number.MAX_VALUE);
        //数字型的最小值
        console.log(Number.MIN_VALUE);
        //无穷大
        console.log(Number.MAX_VALUE*2);
        //无穷小
        console.log(Number.MAX_VALUE*-2);
        //非数字
        console.log('pink'-10);
        
        
        
        
        
        

        
    </script>

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